Switch to newer openstackdocstheme and reno versions

Switch to openstackdocstheme 2.2.0 and reno 3.1.0 versions. Using
these versions will allow especially:
* Linking from HTML to PDF document
* Allow parallel building of documents
* Fix some rendering

Update Sphinx version as well.

Create doc/requirements.txt file and use it, remove docs requirements
from lower-constraints, they are not needed
during install or test but only for docs building.

openstackdocstheme renames some variables, so follow the renames
before the next release removes them. A couple of variables are also
not needed anymore, remove them.

Set openstackdocs_auto_name to use 'project' as name.

Depends-On: https://review.opendev.org/728938
Change-Id: Ic3503a8b38e67e50669428b36f6581cb980d687f

1 files changed, 4 insertions, 0 deletions

diff --git a/tox.ini b/tox.ini
index 7f7ed55..fb4cfd8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -27,11 +27,15 @@ commands =
 commands = {posargs}
 
 [testenv:docs]
+deps =
+  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
+  -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -W --keep-going -b html -d doc/build/doctrees doc/source doc/build/html
 
 
 [testenv:releasenotes]
+deps = {[testenv:docs]deps}
 commands = sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:lower-constraints]